U.S. patent application number 14/956219 was filed with the patent office on 2016-12-15 for tie rod end and method for manufacturing thereof.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Seung Bum Cho.
Application Number | 20160362132 14/956219 |
Document ID | / |
Family ID | 57395035 |
Filed Date | 2016-12-15 |
United States Patent
Application |
20160362132 |
Kind Code |
A1 |
Cho; Seung Bum |
December 15, 2016 |
TIE ROD END AND METHOD FOR MANUFACTURING THEREOF
Abstract
Disclosed are a tie rod end and a method for manufacturing a tie
rod end. The tie rod end includes a ball stud that has a head and a
stud portion connected to one side of the head, a ball seat that
surrounds the head such that the head can move within a
predetermined angle range, a housing that has an internal space for
receiving the head and the ball seat, and a grease pocket that is
formed at a side of the internal space to be applied with a grease
and is surrounded by an outer surface of the other side of the head
and an inner surface of the housing.
Inventors: |
Cho; Seung Bum; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
57395035 |
Appl. No.: |
14/956219 |
Filed: |
December 1, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16C 11/0633 20130101;
F16C 2220/04 20130101; B29C 45/14467 20130101; B29L 2031/30
20130101; F16C 11/068 20130101; B29L 2031/748 20130101; B62D 7/08
20130101; B62D 7/166 20130101; B29C 45/14754 20130101; F16C 11/0685
20130101; B29C 45/14418 20130101 |
International
Class: |
B62D 7/08 20060101
B62D007/08; B29C 45/14 20060101 B29C045/14; F16C 11/06 20060101
F16C011/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 2015 |
KR |
10-2015-0080932 |
Claims
1. A tie rod end comprising: a ball stud that has a head and a stud
portion connected to one side of the head; a ball seat that
surrounds the head such that the head can move within a
predetermined angle range; a housing that has an internal space for
receiving the head and the ball seat; and a grease pocket that is
formed at a side of the internal space to be applied with a grease
and is surrounded by an outer surface of the other side of the head
and an inner surface of the housing.
2. The tie rod end of claim 1, wherein the grease pocket is a
closed space surrounded by the outer surface of the other side of
the head which is opposite to the side of the head where the stud
portion is connected to, and the inner surface of the housing.
3. The tie rod end of claim 1, wherein the internal space of the
housing includes a resin space where injection resin for molding
the ball seat is injected and the grease pocket where the grease is
applied, wherein a height difference exists between a bottom of the
resin space and a top of the grease pocket.
4. The tie rod end of claim 1, wherein a non-spherical portion is
formed at the other side of the head opposite to the side where the
stud portion is connected to, and the grease pocket is a closed
space surrounded by the non-spherical portion of the head inserted
in the housing and the inner surface of the housing.
5. The tie rod end of claim 1, wherein a spherical inner surface of
the housing surrounding a bottom of the grease pocket has a
curvature the same as that of a spherical portion of the head.
6. The tie rod end of claim 1, wherein the ball seat is molded
between the housing and the head by injecting resin into the
internal space of the housing with the head inserted therein.
7. The tie rod end of claim 1, wherein the housing has a resin
injection hole for injecting resin to mold the ball seat.
8. A method for manufacturing a tie rod end, comprising: forming a
housing having an internal space including a grease pocket;
applying a grease to the grease pocket; inserting a head of a ball
stud into the internal space of the housing, wherein the ball stud
further includes a stud portion connected to one side of the head,
such that an outer surface of the other side of the head surrounds
the grease pocket in cooperation with an inner surface of the
housing; and molding a ball seat between the housing and the head
by injecting resin into the internal space of the housing, wherein
the ball seat surrounds the head and the head is movable.
9. The method of claim 8, wherein the internal space of the housing
includes a resin space where the resin for molding the ball seat is
injected and the grease pocket where the grease is applied, wherein
a height difference exists between a bottom of the resin space and
a top of the grease pocket.
10. The method of claim 8, wherein in molding the ball seat, the
resin is injected into the internal space of the housing through a
resin injection hole formed at a side of the housing.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority of Korean Patent
Application Number 10-2015-0080932 filed on Jun. 9, 2015, the
entire contents of which are incorporated herein for all purposes
by this reference.
BACKGROUND
[0002] Technical Field
[0003] The present disclosure relates to a tie rod end and a method
for manufacturing the tie rod end. More particularly, it relates to
a tie rod end of an automotive steering system and a method for
manufacturing the tie rod end.
[0004] Background Art
[0005] In general, an automotive steering system includes a
steering wheel disposed in front of a driver's seat, a steering
shaft connected to the lower portion of the steering wheel, and a
gear box crossing the lower end of the steering shaft and
converting rotational motion force transmitted from the steering
shaft into straight motion force in the left and right of a
vehicle.
[0006] The gear box has a rack bar sliding left/right therein and
tie rods are coupled to both ends of the rack bar through tie rod
ends.
[0007] In detail, the rack bar extends left and right in a hollow
rack housing forming the external shape of the gear box and can
slide axially.
[0008] Tie rods and tie rod ends are coupled to both ends of the
rack bar and tire wheels for steering are coupled to the tie rod
ends.
[0009] Herein, the tie rod end is disposed between the rack bar and
the tie rod to axially transmit power and enable swinging and
rotating.
[0010] Such tie rod ends have been disclosed in Korean Patent
Application Publication No. 10-2006-0104385 and Korean Patent No.
10-1357452.
[0011] Meanwhile, FIGS. 1 to 3 are views illustrating different
kinds of tie rod ends of the related art.
[0012] The tie rod end of the related art illustrated in FIG. 1,
which is a bottom caulking type tie rod end, is manufactured by
inserting a ball stud 114 functioning as a spheroid joint and a
ball seat 113, which surrounds and protects a side of the ball stud
111 and adjusts a friction force between the ball stud 111 and a
housing 112, into the housing 112, closing an opening 115 of the
housing 112 with a cap 114, and fixing the edge of the cap 114 by
caulking the lower end of the housing 112.
[0013] In this case, grease is applied to the inner side of the
ball seat 113 and the ball seat 113 is combined with the ball stud
111 and then inserted into the housing 112.
[0014] The tie rod end of the related art illustrated in FIG. 2,
which is a top caulking type (or CAP-less type) tie rod, is
manufactured by inserting a ball stud 121 functioning as a spheroid
joint and a ball seat 123, which surrounds a side of the ball stud
121 and adjusts a friction force between the ball stud 121 and a
housing 112, into the housing 122, and then fixing the ball stud
121 in the housing 122 by caulking the top of the housing 122.
[0015] In this case also, grease is applied to the inner side of
the ball seat 123 and the ball seat 123 is combined with the ball
stud 121 and then inserted into the housing 122.
[0016] However, the bottom caulking type tie rod of the related art
is manufactured through an easy process, but the caulking portion
of the housing 112 cannot be plated/painted and gets quickly rusty
and torque is largely distributed by caulking distribution.
[0017] As for the top caulking type tie rod end of the related art,
the non-plated caulking portion is not exposed to the outside, so
it is strong against rust, but torque is largely distributed too by
caulking distribution.
[0018] The tie rod end of the related art illustrated in FIG. 3,
which is an insert molding type tie rod end for improving the
defects of the tie rod ends illustrated in FIGS. 1 and 2, is
manufactured by inserting a ball stud 131 and a spacer 134 into a
housing 132 and then insert molding a ball seat 132 in the housing
132 by injecting plastic resin for molding the ball seat 133
through an injection hole formed through the bottom of the housing
132.
[0019] In this case, it is impossible to apply grease to the inner
side of the ball seat 132 due to the insert molding of the ball
seat 132 and it is also impossible to apply grease to an outer side
of the ball stud 131 (grease slides), so a spacer 134 having a
grease pocket is additionally provided between the ball stud 131
and the bottom of the housing 132 in order to define a space to
keep grease, thereby ensuring a grease pocket for keeping
grease.
[0020] The insert molding type tie rod end does not undergo
caulking, so there is no need for omitting plating/painting for
caulking, anti-rust is strong and distribution of torque due to
caulking distribution reduces. However, since the spacer 134 is
added, the numbers of parts and manufacturing processes
increase.
[0021] The information disclosed in this Background section is only
for enhancement of understanding of the general background of the
invention and should not be taken as an acknowledgement or any form
of suggestion that this information forms the prior art already
known to a person skilled in the art.
SUMMARY OF THE DISCLOSURE
[0022] The present invention has been made in an effort to solve
the above-described problems associated with prior art and/or other
problems.
[0023] In one aspect, the present invention provides a tie rod end
which has a grease pocket for keeping grease needed between a ball
stud and a ball seat and of which the numbers of parts and
manufacturing cost may be reduced by removing a spacer used in the
related art, and a method for manufacturing the tie rod end.
[0024] In a preferred embodiment, a tie rod end includes: a ball
stud that has a head and a stud portion connected to one side of
the head; a ball seat that surrounds the head such that the head
can move within a predetermined angle range; a housing that has an
internal space for receiving the head and the ball seat; and a
grease pocket that is formed at a side of the internal space to be
applied with a grease and is surrounded by an outer surface of the
other side of the head and an inner surface of the housing.
[0025] In an aspect, the grease pocket is a closed space surrounded
by the outer surface of the other side of the head, which is
opposite to the side of the head where the stud portion is
connected to, and the inner surface of the housing, and a spherical
inner surface of the housing surrounding a bottom of the grease
pocket has a curvature the same as that of a spherical portion of
the head.
[0026] The internal space of the housing includes a resin space
where injection resin for molding the ball seat is injected and the
grease pocket where the grease is applied, wherein a height
difference exists between a bottom of the resin space and a top of
the grease pocket to prevent the resin from flowing into the grease
pocket.
[0027] In another preferred embodiment, a non-spherical portion is
formed at the other side of the head opposite to the side where the
stud portion is connected to, and the grease pocket is a closed
space surrounded by the non-spherical portion of the head inserted
in the housing and the inner surface of the housing.
[0028] In still another preferred embodiment, the ball seat is
molded between the housing and the head by injecting resin into the
internal space of the housing with the head inserted therein and
the housing has a resin injection hole for injecting resin to mold
the ball seat.
[0029] In another aspect, the present invention provides a method
for manufacturing a tie rod end. The method includes: forming a
housing having an internal space including a grease pocket;
applying a grease to the grease pocket; inserting a head of a ball
stud into the internal space of the housing, wherein the ball stud
further includes a stud portion connected to one side of the head,
such that an outer surface of the other side of the head surrounds
the grease pocket in cooperation with an inner surface of the
housing; and molding a ball seat between the housing and the head
by injecting resin into the internal space of the housing, wherein
the ball seat surrounds the head and the head is movable.
[0030] According to the tie rod end and the method for
manufacturing the tie rod end, since it is possible to directly
machine and secure a grease pocket at a side of a housing, there is
no need for a spacer used in the related art, so the number of
parts decreases and the manufacturing cost/weight and a package are
reduced. Further, since there is no need for a process of inserting
a spacer, the manufacturing process reduces and the rate of
problems with quality may be reduced.
[0031] Other aspects and preferred embodiments of the invention are
discussed infra.
[0032] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (for example, fuels derived from
resources other than petroleum). As referred to herein, a hybrid
vehicle is a vehicle that has two or more sources of power, for
example both gasoline-powered and electric-powered vehicles.
[0033] The above and other features of the invention are discussed
infra.
[0034] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The above and other features of the present invention will
now be described in detail with reference to certain exemplary
embodiments thereof illustrated in the accompanying drawings which
are given hereinbelow by way of illustration only, and thus are not
limitative of the present invention, and wherein:
[0036] FIG. 1 is a view illustrating a bottom caulking type tie rod
end according to the related art;
[0037] FIG. 2 is a view illustrating a top caulking type tie rod
end according to the related art;
[0038] FIG. 3 is a view illustrating an insert molding type tie rod
end according to the related art;
[0039] FIG. 4 is a view illustrating a tie rod end according to an
embodiment of the present invention;
[0040] FIG. 5 is a view illustrating a housing of the tie rod end
according to an embodiment of the present invention; and
[0041] FIG. 6 is a view illustrating a method for manufacturing a
tie rod end according to an embodiment of the present
invention.
[0042] Reference numerals set forth in the Drawings includes
reference to the following elements as further discussed below:
TABLE-US-00001 10: housing 11: internal space 12: head space 13:
resin space 14: grease injection hole 15: resin injection hole 16:
opening 20: ball stud 21: head 22: stud portion 23: non-spherical
portion 24: spherical portion 30: ball seat
[0043] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various preferred features illustrative of the
basic principles of the invention. The specific design features of
the present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0044] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0045] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that present description is not
intended to limit the invention(s) to those exemplary embodiments.
On the contrary, the invention(s) is/are intended to cover not only
the exemplary embodiments, but also various alternatives,
modifications, equivalents and other embodiments, which may be
included within the spirit and scope of the invention as defined by
the appended claims.
[0046] As illustrated in FIG. 4, a tie rod end according to the
present invention includes a housing 10, and a ball stud 20 and a
ball seat 30 inserted in the housing 10.
[0047] The ball stud 20 is composed of a spherical head 21
functioning as a spheroid joint and a bar-shaped stud portion 22 at
a side of the head 21. The head 21 has a non-spherical portion 23
on the outer side of the other side opposite to the side where the
stud portion 22 is integrally connected or monolithically
formed.
[0048] The non-spherical portion 23 may be machined in a flat shape
and the contact area with the ball seat 30 depends on the size of
the non-spherical portion 23, so it is possible to adjust torque by
contact with the ball seat 30 by appropriately adjusting the area
of the non-spherical portion 23.
[0049] The ball seat 30 is molded and inserted in the housing 10 by
molding or injection molding, surrounds the other portion of the
outer side of the head 21 except for the non-spherical portion 23
(e.g., most part of the spherical portion 24), and has a spherical
inner side so that the ball stud 20 can freely rotate within a
predetermined angle (operation angle) range therein.
[0050] The ball seat 30 surrounds and protects the head 21, adjusts
a friction force between the head 21 and the housing 10, and is
molded between the housing 10 and the head 21 by injection resin
injected into the housing 10.
[0051] To this end, a resin injection hole 15 for injecting
injection resin for molding the ball seat 30 is formed at the
opposite side to the opening 16 in the housing 10.
[0052] As illustrated in FIG. 5, the housing 10 has an internal
space 11 where the head 21 and the ball seat 30 are inserted and
the internal space 11 has a substantially spherical shape with a
side open.
[0053] In detail, the internal space 11 has a head space 12 at the
center where the head 21 is inserted, a resin space 13 where the
ball seat 30 is molded and disposed around the outside, and a
grease pocket 14 where grease for lubrication between the ball seat
30 and the head 21 is applied and filled, at the lower portion.
[0054] The head space 12 and the grease pocket 14 define a
spherical space and the resin space 13 is defined around the outer
side of the head space 12, thereby defining a space substantially
corresponding to the ball seat 30.
[0055] The grease pocket 14 is formed by machining a portion of the
inner side of the housing 10 which faces the non-spherical portion
23 of the head 21, in detail, between the non-spherical portion 23
of the head 21 inserted in the internal space 11 of the housing 10
and the portion opposite to the opening 16 of the inner side of the
housing 10.
[0056] When the head 21 is inserted in the internal space 11 of the
housing 10, the non-spherical portion 23 of the head 21 is placed
over the grease pocket 14 and the top of the grease pocket 14 is
surrounded by the non-spherical portion 23, so a closed spaces is
defined by the non-spherical portion 23 of the head 21 and the
inner side of the spherical surface (curved surface) of the housing
10.
[0057] Herein, a portion of the inner side of the housing 10
surrounding the bottom of the grease pocket 14 is machined in a
spherical shape having a curvature the same as that of the
spherical portion 24 of the head 21, and as illustrated in FIG. 4,
and forms a sphere having a predetermined curvature in cooperation
with the spherical portion 24 of the head 21 placed over the grease
pocket 14.
[0058] When injection resin (e.g., plastic resin) for molding the
ball seat 30 is inserted into the housing 10, in order to prevent
the plastic resin from flowing into the grease pocket 14, a step
having a height difference is formed between the top of the grease
pocket 14 and the bottom of the resin space 13 in the housing
10.
[0059] Herein, a method for manufacturing a tie rod end according
to some embodiments of the present invention is described hereafter
with reference to FIG. 6.
[0060] First, a housing 10 having an internal space 11 open at a
side is formed as a housing of a tie rod end.
[0061] In this case, the internal space 11 includes a head space
12, a resin space 13, and a grease pocket 14 and it is possible to
secure a spherical surface (curved surface) corresponding to the
outer side the a ball seat 30 by machining the inner side of the
housing 10 close to the inner space 11 and a spherical surface
(curved surface) making (or surrounding) a side (the bottom) of a
grease pocket 14.
[0062] Next, grease for lubrication between the ball seat 30 and
the head 21 is applied and filled in the grease pocket 14.
[0063] Next, the head 21 of a prepared ball stud 20 is inserted
into the internal space 11 of the housing 10 to be placed over the
grease pocket 14 in the head space 12 and the ball seat 30
surrounding the head 21 such that the head can move is
injection-molded between the housing 10 and the head 21 by
injecting injection resin for molding the ball seat 30 in the
internal space 11.
[0064] In this case, the ball stud 20 and the housing 10 are fixed
at a predetermined position on a mold for insert molding of the
ball seat 30 such that the housing 10 and the ball stud 20 are not
moved, and then the ball seat 30 is molded by injecting injection
resin into the resin space 13 in the internal space 11 through a
resin injection hole 15 in the housing 10.
[0065] Herein, as the head 21 is inserted into the internal space
11 of the housing 10 to be placed over the grease pocket 14, the
outer side (that is, a non-spherical portion) at the other side of
the head 21 opposite to a stud portion 22 surrounds and closes the
grease pocket 14 in cooperation with the inner side of the housing
10.
[0066] For convenience in explanation and accurate definition in
the appended claims, the terms "inner" or "outer", "left" or
"right", and etc. are used to describe features of the exemplary
embodiments with reference to the positions of such features as
displayed in the figures.
[0067] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments.
* * * * *